its a 97 gmc 2500 with the vortec 7.4l p1345 is the only code popping up i dont have a scan tool just code reader so i tested cmp and ckp with dmmon volts dc mode cmp has pwr and grnd and is switching on and off ckp on the other hand has pwr and grnd but did not switch on/off just stayed on at 5v and i turn engine manually at least 3 full revolutions dist. is secure rotor had some freeplay but i dont think it was on the shaft itself cmp is not loose either so i changed out ckp and code still comes back after i clear it also the 20 amp ecm l fuse keeps popping should i backprobe pcm i need some advice anyone have experience with this thank you

 

On your truck the distributor is the cam sensor. It is not used to set ignition timing. Turning it synchronizes the cam and crank sensors and does not set ignition timing as it did in older trucks. To set the "timing " (synchronization) you must have a scan tool that shows data. You have to monitor the data as you turn the dis. the spec is 0 +or- 2 anything to far away from that spec will set p1345. If the dis has been out of the truck then it is installed incorrectly. If it has never been out the either the dis itself is going bad or the gear is worn out (most likely). If you do not have the scan tool there is really nothing you can do. You need to see what that spec is currently before you do anything else.